Process for drying paper.



B. P. BUTTS.

PROGESS FOR DRYING PAPER.

APPLIOATION FILED 8EPT.13,191L

Patented Apr. 21, 19M

2 SHEETS*SHEET1.

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ma/m6 fldm BY AYTURNEK E. P. BUTTS.

PROCESS FOR DRYING PAPER. APPLICATION FILED SEPT. 13, 1911.

1,094,195 Patented Apr. 21, 191a 2 SHEETS$HEET 2.

I I I 8 IVVENTOR,

f v 7 Edward BBZJZZJL ATTORNEY.

EDWARD P. BUTTS, OF SPRINGFIIELD, MASSACHUSETTS.

raocn'ss roe DRYING PAPER.

Specification of Letters Patent.

Patented Apr. 21, 1914.

Application filed September 13, 1911. Serial No. 649,151.

To all whom it may concern:

. Be it known that I, EDWARD P. Burrs, a citizen of the United States of America, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Processes for Drying Paper, of which the following is a specification.

This invention relates to improvements in processes for drying paper.

Broadly, the invention consists in modifying the condition of atmospheric air so as to enable it to take up or absorb definite quantities of moisture. This feature is very desirable in the manufacture of paper, particularly in that part of the making which relates to the drying and lofting process.

It is a well known fact that the quantity of moisture contained in the atmosphere varies from day to day with relation to its saturation point. This variation of course materially affects the rate at which it will absorb any additional moisture. For this reason the rate of drying paper depends very materially upon the per cent. of moisture contained in the air of the drying room. Some days it is very dry, and others very much saturated. On the days that the air is very dry the output of the mill is greatly increased, while on the moist days the output is very much lessened. The output is therefore uneven both in quantity and quality, due to this lack of uniform conditions in the process.

A feature of my invention is that it makes possible the maintenance of a uniform condition readily changed and made suitable for any particular quality of product affording rapid drying or lofting for a paper requiring such treatment, or slower drying or lofting for a paper requiring such conditions.

Another feature of my invention is that each quantity of paper is dried or lofted in the shortest possible time which develops the maximum product for these departments in any existing plant and requires a smaller out-lay in the construction of the new plants.

In general, my invention consists in modifying the condition of the air that is sent to the drying or lofti'ng rooms so that its capacity to absorb moisture is practically definite and uniform for any particular grade and weight of paper to be treated, whereby the output of dried paper is materially in-' creased and the product rendered uniform from day to day.

In the drawings forming part of my application,and which illustrate one form of apparatus in which my invention may be carried out,-Figure 1 is a plan view of the apparatus showing the heating coil, shower pipes, the thermostat, and the inclosing casmg. Fig. 2 is a side view of the same illustrating the interior construction thereof. Fig. 3 is an edge view of one of the sections of the heating coils. Fig. 4 is a view in side elevation indicating paper suspended in lofting room in the usual manner and inlet and outlet plpes to permit the conditioned air to enter and escape therefrom. Fig. 5 is a view similar to Fig. 4 but showing the suspended paper in side elevation. Fig. 6 is a V ew similar to Fig. 4 but showing the conohtioned air applied to the paper on a drying machine with the inlet and escape pipes for the air. Fig. 7 is a view of Fig. 6 in side elevation showing the position of the air inlet pipes.

Referring to the drawings in detail, a designates the casing member, one end of which is provided with a suction fan 6. Located within the casing, adjacent the outlet end of the suction fan, are a series of pipes 0 provided with nozzles dfor producing a fine spray effect of the water, so that when the air leaves the fan and passes through the spray it will be thoroughly saturated when it leaves the spray. The water from the spray is caught in the lower part of the casing, as shown at e, where it escapes therefrom by means of the trap f. Placed beyond the spray g are a series of plates it against which the saturated air strikes so that the surplus or entrained Water contained therein is separated therefrom when it strikes these plates. After the air leaves these plates it passes over a series of heating coils 2' which have their ends connected to the upper and lower drums j and 0, the upper drum being connected with a steam supply pipe m. Located within this pipe is a valve 0.

p designates a steam gage to indicate the pressure within the sup-ply pipe m, and consequently that supplied to the coils z.

Connected to the valve 0 is a thermostat 1' by means of a suitable connection .9 whereby the flow of steam to the coils i may be regulated to produce and maintain any desired temperature of the air as it leaves the coils and before it passes from the casing for use in the drying or lofting rooms. Therefore,

the temperature of the saturated air is changed after it leaves the plates h and before it escapes from the casing a at the point 2 from which point it passes on to the drying room.

u designates a trap which is attached to the drum to carry away the water of condensation.

From this apparatus it is clear that the temperature of the air, after it leaves the spray of water 9, is the same as that of the water, say for example Fahrenheit, and that the air is of course in a saturated condition. It is also clear that if the temperature of this saturated air is raised, say to 80 Fahrenheit, it will be in a condition to absorb or take up more moisture.

Referring now to the manner in which my improvement is applied to the drying of paper either While in the loft or passing through the drying machine, 3 designates the floor line of the drying room and 1 the beams for supporting the bars 5 on which the sheets of paper 6 are suspended. The conditioned air as it leaves the outlet shown at t in Figs. 1 and 2 enters the drying room or loft'by means of pipe 7 and after passing upward through the drying room it escapes therefrom by means of the pipe shown at 8, entrance to this pipe being shown at 9. These two pipes are provided with suitable dampers or regulators indicated at 10 and 11 whereby the rapidity or rate of motion of the air through the drying loft is varied. After the air has taken up moisture in passing through the drying loft it is again drawn from the drying loft through the pipe 8 which leads back to the fan 6, shown in Figs. 1 and 2 and is again passed through the spray of water shown at g, and its temperature again raised to the desired quantity, and a second time is drawn through the drying loftas described.

As showing the application of my invention to a paper drying machine reference is made to Figs. 6 and 7 in which the drying rolls are indicated at 12 over which the web of paper passes shown at 13. The conditioned air from the outlet pipe 2? passes by means of the pipe 14 to the drying machine in which are placed dampers 15. The air from the pipe 1 1 passes upward through the pipe 16 and escapes at the outlet opening 17 as indicated by the arrows at 18 which causes the conditioned air to be blown parallel with the axis of the drying rolls and constantly into contact with the paper 13. The damper 19 is placed in the pipe 16 after the air has escaped from the pipe 16 and passed in contact with the web of paper and it is drawn through the pipe 20 which leads back to the fan 0?. Suitable dampers or controlling devices are placed in the entrance or inlet openings 21 whereby the passa e or rate of motion of the conditione air through the drying machine is controlled.

By adjusting the temperature of the air as it leaves the casing a at the point t, it will be seen that this heated air, when it enters the drying room, is in condition to absorb a definite amount of moisture in drying or lofting the paper, which condition may be changed at will, regardless of the moisture condition of the outside atmospheric air, to a capacity for absorbing a greater or less amount, as required for the particular grade or weight of paper to be treated. This method of causing air of exactly the same capacity for absorbing moisture to enter the drying room, whereby a definite amount of moisture will be taken up by the heated air, is one that greatly increases the quantity of paper dried or lofted, and at the same time renders the same uniform in both quantity and in quality for each particular grade from day to day. The air, after it leaves the drying room, may, if desired, be carried or drawn back to the casing by means of the fan I) and again sent to the drying room.

What I claim is:

The process of drying paper with air having a predetermined moisture absorbing capacity, which consists in first effecting the saturation of the air by direct contact with water having a definite temperature, then directing the saturated ainagainst an obstruction to separate therefrom the surplus of water, then directing theair against a heated surface having a definite temperature .to efiect the expansion of the air, next liberating the dried and heated air and causing it to pass over the paper to be dried, and finally collecting the moisture laden air to again be saturated and used as herein stated.

EDWARD P. BUTTS. Witnesses:

K. I. CLEMoNs, HARRY W. BOWEN. 

